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Gimp for astrophotos, tutorial

astrophotography
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#1 Astrofriend

Astrofriend

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Posted 26 March 2020 - 10:52 AM

Hi,
Have you noticed how advanced Gimp has been with the new version 2.10 ?

Now it work perfekt to open Fits 32 bit floating point images and process them. I have tried this many times earlier but it never worked very good. Now it's like a dream to work with.

 

I'm in the learning process how to use Gimp's capabilities. I have now got the opening process of three grey rgb images to work. It's of course not very complicated, but for me who never used Photoshop or something simular it was and I had hard to find a tutorial for the new version.

 

I have now made a tutorial for this first step how to start with Gimp and open 32 bits separated color images:

http://www.astrofrie...troduction.html

 

If you already working with Gimp, have you found something of special interest ?

 

Lars


  • Gary Z, ratnamaravind, scottmm2012 and 1 other like this

#2 nitegeezer

nitegeezer

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Posted 26 March 2020 - 02:02 PM

I am excited to see you making tutorials in GIMP! I believe you are the one who made multiple tutorials for Fitsworks which has helped me a lot. I have been using GIMP since their 2.9 version which was the in development version leading to 2.10. I have mainly used the Levels and Curves features, but I know there is a whole lot more there to learn.

#3 Astrofriend

Astrofriend

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Posted 27 March 2020 - 08:37 AM

Hi Chuck,
It may be me who is guilty of Fitswork tutoring. I made four videos on Youtube a few years ago.

Videos are nice to watch, but give me some trouble. If I find a better method of doing it or maybe something wrong I say then it is quite difficult to edit it in the form of a video. If I have it on my own website in the form of pictures and text, I can correct errors very quickly.

What I am looking for good working methods in Gimp to date are:
1:
How do I remove the background with light pollution?

2:
How do I mask stars so that the background and the weak objects can be edited without affecting the stars.

Something that also worries me is the support and updates of DCRaw. Almost all older astronomy programs are based on DCRaw when reading raw files, new cameras' raw files can not be read without an update of DCRaw. Gimp has some other solution to do this.

 

ps.

Nice little observatorium you have and it looks to be at a dark place too.

/ Lars


Edited by Astrofriend, 27 March 2020 - 08:39 AM.


#4 Astrofriend

Astrofriend

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Posted 27 March 2020 - 11:49 AM

Today I practiced how to remove the light polluted background in Gimp. I used a standard filter, the Despeckle filter in Gimp. It worked great but the test image was an easy one.

 

Here is how I did it, see page 4:

http://www.astrofrie...troduction.html

 

Next thing for me to learn is how to mask out the stars.

 

/Lars




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